权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular biological and histomorphometrical study on bone remodeling and root resorption during orthodontic tooth movement.

正畸牙齿移动过程中骨重塑和牙根吸收的分子生物学和组织形态学研究。

基本信息

批准号：
07457508
负责人：
TAKANO Teruko
金额：
$ 4.29万
依托单位：
The UNIVERSITY of TOKUSHIMA
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

In the present study, the gene expression for osteopontin (OPN) and osteocalcin (OSC) in the alveolar bone was investigated by in situ hybridization histochemistry with non-radioisotopic digoxigenin 11-UTP labeled cRNA prove for OPN and OSC in rat maxillary dent-alveolar unit containing molars and intact PDL following a single loading to produce a well synchronized wave of complete remodeling. From these experiments we found osteocytes respond to mechanical loading in vivo with expression of mRNA for OPN but not for OSC,to associate with subsequent bone resorption. On day 0 an intense positive signal of mRNA for OSC but not OPN was demonstrable at osteoblasts on the distal surface of the interradicular septum of buccal roots of the maxillary first molar of 7-week-old rat. After insertion of an elastic band between the first and second molars the PDL facing the distal surface of the interradicular septum was compressed and the periodontal space on day 1 became narrower than that on day … More 0. At the time the positive signal of OSC mRNA disappeared from cells covering the distal surface of interradicular septum under the compressive strain environment. On the contray, a positive signal of mRNA for OPN was intensely expressed at oseocytes within the matrix in the distal half of the interradicular septum but not in the mesial half, and around the apex of buccomesial root, where the change of consequent compressive strains following a tipping movement of the first molar must occur. Thses osteocytes had large and roudish nuclei, and their osteocyte lacunae became enlarged compared with those on day 0. On day 3, as the compression of PDL continued, lining cells disappeared from the bone surface facing PDL and bone resorption on the distal region of the interradicular septum actively occured. The undermining resorption areas of alveolar bone were prominently eveident, and there were many osteoclasts making Howship's lacunae and a plenty of mononuclear cells around resorbing bone surfaces, where bone matrix containing OPN mRNA expressing osteocytes had been present on day 1. A positive signal of OPN mRNA expressed intensely in osteocytes, multinucleated cells adjacent to Howship's lacunae, designated as osteoclasts, and mononuclear cells on day 3. On the contrary, gene expression for OSC could not be observalbe at these areas.These results suggest that at the beginning of a remodeling cycle stimulated by mechanical force, the OPN in osteocytes promotes osteoclast attachment and activation (stage 1), leading to the resorption phase (stage 2) and that osteocytes play an important role for mechanosensor. Less

本研究采用原位杂交组织化学技术，以非放射性同位素地高辛标记的cRNA为探针，研究了大鼠上颌牙槽骨单位（含磨牙和完整PDL）在单次负荷后骨桥蛋白（OPN）和骨钙素（OSC）基因在牙槽骨中的表达。从这些实验中，我们发现骨细胞在体内对机械负荷有反应，表达OPN的mRNA，但不表达OSC的mRNA，与随后的骨吸收有关。在第0天，在7周龄大鼠上颌第一磨牙颊根的根间隔膜远侧表面的成骨细胞中，可观察到OSC而非OPN mRNA的强阳性信号。在第一磨牙和第二磨牙之间插入弹性带后，牙周膜朝向根间隔远中面受到压缩，牙周间隙在第1天比第2天变窄 ...更多信息 0.在压应变环境下，覆盖在根间隔远侧表面的细胞中OSC mRNA的阳性信号消失。OPN mRNA在根间隔远中端基质内的骨细胞中表达较强，而在近中端和颊根尖周围的骨细胞中表达较弱，而第一磨牙倾斜运动后，颊根尖周围的骨细胞中OPN mRNA表达较弱。骨细胞核大而圆，骨细胞陷窝较第0天扩大。在第3天，随着PDL的继续压缩，衬里细胞消失，从骨表面面临PDL和骨吸收的远侧区域的根间隔积极发生。牙槽骨的破坏性吸收区明显，形成Howship骨陷窝的破骨细胞较多，吸收骨表面周围有大量单核细胞，第1天已出现含OPN mRNA表达骨细胞的骨基质。第3天，骨桥蛋白mRNA的阳性信号在骨细胞、邻近Howship陷窝的多核细胞（称为破骨细胞）和单核细胞中强烈表达。这些结果表明，在机械力刺激的重塑周期的开始，骨细胞中的OPN促进破骨细胞的附着和激活（第1阶段），导致吸收阶段（第2阶段），骨细胞在机械传感器中起着重要作用。少